Toshiaki Kato

Transfusion-transmitted hepatitis E caused by apparently indigenous hepatitis E virus strain in Hokkaido, Japan

BACKGROUND:  In industrialized countries, sporadic cases of hepatitis E have been reported in individuals who have never been in an endemic area. Hepatitis E virus (HEV) infection commonly occurs via the fecal‐oral route but a potential risk of transfusion transmission route has been suggested.

A case of transfusion‐transmitted hepatitis E caused by blood from a donor infected with hepatitis E virus via zoonotic food‐borne route

BACKGROUND: Five cases of transfusion transmission of hepatitis E virus (HEV) have been reported so far. The infection routes of the causative donors remain unclear, however. Also, the progress of virus markers in the entire course of HEV infection has not been well documented.

A New Platelet-Specific Antigen, Naka, Involved in the Refractoriness of HLA-Matched Platelet Transfusion

Abstract. Serum from a thrombocytopenic patient who was refractory to the transfusions of HLA‐matched platelets contained a platelet‐specific alloantibody, anti‐Naka. Immunofluorescence analyses revealed that the Naka antigen defined by the serum was expressed exclusively on platelets and its distribution was different from PlA1, Baka, Yuka or Yukb. Analysis by Dr. von dem Bornes group revealed the Naka was also different from Koa, Kob or Zwb. Family studies showed that the Naka antigen was inherited as an autosomal codominant trait. Its antigen frequency in the Japanese population was over 97%. The results of the enzyme immunoassay using monoclonal antibodies for antigen immobilization showed that the Naka epitope did not appear to reside on GPIIb/IIIa or Ib. The transfusions of Naka‐compatible platelets improved the patients thrombocytopenia.

Reduction in adverse reactions to platelets by the removal of plasma supernatant and resuspension in a new additive solution (M-sol).

BACKGROUND: Leukodepletion reduces but does not eliminate adverse reactions to platelet concentrate (PC). As an alternative strategy, plasma reduction or washing of platelets should be considered. However, the efficacy of this strategy is still unclear.

Comparison of the sensitivity of NAT using pooled donor samples for HBV and that of a serologic HBsAg assay

BACKGROUND : Studies were conducted using samples from early and late‐stage HBV‐infected persons to determine the pool size at which PCR had better sensitivity than a sensitive HBsAg chemoluminescence immunoassay (CLIA‐HBsAg).

Biologic activity of RANTES in apheresis PLT concentrates and its involvement in nonhemolytic transfusion reactions

BACKGROUND: RANTES, one of the PLT‐derived biologic response modifiers, accumulates in PLT concentrates (PCs) during storage and may play a causative role in nonhemolytic transfusion reactions (NHTRs) after PC transfusion.

A nationwide survey for hepatitis E virus prevalence in Japanese blood donors with elevated alanine aminotransferase

BACKGROUND: Although we reported two cases of transfusion‐transmitted hepatitis E in Japan, the prevalence of hepatitis E virus (HEV) in Japanese blood donors is not very clear.

A nationwide survey for prevalence of hepatitis E virus antibody in qualified blood donors in Japan

Background and Objectives  In previous studies, we reported the transmission of hepatitis E virus (HEV) by transfusion, and the frequent detection of HEV markers in Japanese blood donors with elevated ALT levels. For the current study, we carried out a nationwide survey of the prevalence of IgG anti‐HEV in qualified blood donors throughout Japan.

Establishment of cell lines stably expressing HNA-1a, -1b, and -2a antigen with low background reactivity in flow cytometric analysis.

BACKGROUND: Antibodies to neutrophil antigens have been implicated in neonatal alloimmune neutropenia, autoimmune neutropenia, and transfusion‐related acute lung injury. Most often, neutrophil‐specific antibodies are directed toward human neutrophil antigen (HNA)‐1 (Fcγ receptor 3b) and HNA‐2a (CD177) in these disorders.

Generation of inflammatory cytokines and chemokines from peripheral blood mononuclear cells by HLA Class II antibody-containing plasma unit that was associated with severe nonhemolytic transfusion reactions.

BACKGROUND: HLA Class II antibodies are thought to be involved in severe transfusion reactions including transfusion‐related acute lung injury (TRALI). The activation of monocytes by HLA Class II antibody may play an important role in the etiology of TRALI.